This application is filed under 35 U.S.C. 371 and claiming priority from PCT/EP97/05799, filed Oct.30, 1996.
1. Field of the Invention
This invention relates to water-free surfactant mixtures with a reduced potential for irritation containing various alcohol sulfates in selected mixing ratios and to their use for the production of surface-active compositions.
2. Priot Art
By virtue of their favorable performance properties and their excellent ecotoxicological compatibility, fatty alcohol sulfates represent anionic surfactants which are acquiring increasing significance for the production of laundry detergents, dishwashing detergents and cleaning compositions.
Highly concentrated, aqueous or water-free solid formulations of anionic surfactants are of course desirable for storage and transportation purposes. Unfortunately, such formulations are attended by the disadvantage that, in contrast to the products diluted to the in-use concentration, they have a highly irritating effect on the skin and mucous membrane which means that more stringent safety-in-use requirements have to be satisfied for marketing. Another disadvantage is that known compositions do not possess sufficient flowability or solubility, especially in cold water.
The use of mixtures of fatty alcohol sulfates based on tallow and coconut alcohol in a ratio by weight of 9:4 to 1:6 for the production of detergents with improved detersive propertiescleaning performance is known from European patent application EP 0 342 917 A2 (Unilever). More particularly, this document describes mixtures of tallow alcohol sulfate and cocoalcohol sulfate in a ratio by weight of 60:40 to 40;60. However, it does not mention either the irritation potential of the mixtures described therein or their flowability or solubility.
European patent application EP 0 554 991 (Unilever) describes water-containing detergent mixtures based on alkyl sulfates in which at least 25% by weight of the alkyl chains contain 10 or 11 carbon atoms. These alkyl chains may be linear, branched, odd-numbered or even-numbered alkyl chains. In addition, these short-chain alkyl sulfates may be mixed with cocoalcohol sulfate. Since these detergent mixtures additionally contain betaines or amine oxides, they show good dermatological compatibility. However, the document in question does not refer either to the solubility or to the flowability of the alkyl sulfates,
Accordingly, the complex problem addressed by the invention was to provide new water-free surfactant mixtures based on alcohol sulfates which would be distinguished both by a significantly reduced irritation potential and by improved flowability and solubility.